Von Miller grabs his knee against the Houston Texans Sunday. He tore his left ACL and will miss the remainder of the season. / Thomas Campbell, USA TODAY Sports

by Lindsay H. Jones, USA TODAY Sports

by Lindsay H. Jones, USA TODAY Sports

ENGLEWOOD, Colo. -- Chaos has become the norm for the Denver Broncos this season, yet even this news came as a shock as players showed up to the team facility for film sessions and meetings Monday.

Outside linebacker Von Miller suffered a torn anterior cruciate ligament in his right knee. His season is over, and the Broncos will head into their final regular season game and into the playoffs without their best pass rusher.

Miller injured his knee while being blocked late in the first quarter of Sunday's win at Houston. The team initially feared Miller had torn his ACL but needed an MRI exam to confirm it.

"Truth be told, I said a prayer for him last night. The reality is the MRI proved to be a torn ACL and now we'll move forward," Fox said.

Fox, who was sent home from Dove Valley Monday morning with flu-like symptoms, was pragmatic enough to amend his "next man up" philosophy when it comes to losing Miller, who has 35 sacks since the Broncos drafted him at No. 2 in 2012. He had only five sacks in nine games this season after serving a six-game suspension for violating the NFL's drug policy.

"It's a blow," Fox said. "That's like losing Ryan Clady earlier in the season, or Wes Welker. Any time you take any of those caliber of players, it's a blow. But, next men up kind of approach. Our guys will deal with it, and we have to."

Though the Broncos went 6-0 without Miller earlier this year, Denver's defense has changed immensely in the months since.

This is a defense that has already lost starting defensive tackle Kevin Vickerson (hip) and free safety Rahim Moore (lower leg). Defensive end Derek Wolfe remains on the active roster but hasn't practiced since being hospitalized after suffering seizure-like symptoms on Nov. 29, while cornerback Champ Bailey is finally being eased back after a nagging, season-long foot injury.

"We've been through a lot of adversity, losing a lot of key guys this year," cornerback Chris Harris said. "We've had so much going on, it's like, 'What else bad can happen?' Hey, we're still 12-3, but I mean, everything bad possibly that could happen to a defense has happened this year."

Nate Irving is expected to replace Miller in the Broncos' base defense, just like he did during Miller's suspension. Defensive end Shaun Phillips had 5 1/2 of his team-leading 10 sacks while Miller was suspended. The Broncos added defensive end Jeremy Mincey last week, who now could assume a larger pass-rush role.

The Broncos will add a player to the active roster once Miller is placed on injured reserve. Denver has a pass-rushing defensive end (John Youboty) and linebacker (Brandon Marshall) on its practice squad.

Fox said a date has not yet been set for Miller's surgery, nor a specific timetable for his return. All the Broncos know is that Miller won't be able to help them again this year.

"It's definitely tough losing a guy of his caliber. Him just getting back, halfway through the season, finding his rhythm as a pass rusher â?? you're going to miss him tremendously," wide receiver Eric Decker said. "But we've got guys that are going to have to step up and our depth is getting a little slimmer. But this year, you've got to find a way to be successful."